Vagal tone

The Respiratory sinus arrhythmia (RSA ), and occasionally respiratory arrhythmia, describes the respiratory synchronous variation of the heart rate. If inhaled increases the heart rate at expiration it falls again.

Respiratory rate and heart rate are significant rhythms. They relate to each other and these encounter fluctuations. RSA is a commonly evaluated parameters or a characterizing feature of the interaction between respiration and heart rate.

It was 1860 by Petr Einbrodt ( 1835-1865 ) first described.

Term

Respiratio is the Latin term for breathing. An arrhythmia referred to in medicine, the irregularity in particular in relation to the heart, the word component sine indicates that the site of impulse formation of the sinoatrial node of the heart. In contrast to other arrhythmias in medicine, the RSA is normal. Which means it has no clinical significance but is the body's requirement of a healthy organism.

Measurement

The measurement of respiratory sinus arrhythmia is an established standard methods in the autonomous functional diagnostics to verify the autonomic balance and parasympathetic activity.

The influence of respiration on the heart beat can be done either by finger or ear clip, or an electrocardiogram via a measurement of the pulse (using pulse oximetry ). In most cases, a computer-assisted, the resulting curves are analyzed as a time series. Since the respiratory sinus arrhythmia constitutes a major component of heart rate variability, approximately follows a sinusoidal coupling between respiration and heart rate.

A more specific measurement of the coupling of breathing and heartbeat can be represented by means of spectral measurements at more than 3 minutes for example. It is used to determine from which frequency components in addition to the respiratory sinus arrhythmia, the heart rate variability composed.

Quantity and quality of respiratory sinus arrhythmia is considered medically and scientifically based on the amplitude of the heart rate change within a representative breath of 6 consecutive breaths described ( EI difference, RSA).

Pathophysiology

The respiratory arrhythmia is a normal finding, which occurs pronounced in children and adolescents. With age, the ability to make this flexible response of heart beat to the respective requirements decreases.

An excessively regular heart rate that has no signs of respiratory sinus arrhythmia may indicate asphyxia in newborns.

Research

A study by the Medical University of Hannover in 2002 showed with trauma patients that successful psychotherapeutic treatment also improves the ability to process stress. The results of the study also showed improved heart rate variability after successful therapy. The analysis of respiratory -related heart rate fluctuations can serve as measurable information for the therapist and patient. It provides information about the degree of ability to regulate the autonomic nervous system. Currently, it is checked whether an increase of heart rate variability in general improves the ability to regulate stress.

The cardiorespiratory interaction is inter alia importance in infant research, as well as in the risk stratification of heart patients and diabetics.

Another study deals with the autonomic control of heart rate and its coordination with the respiratory system in sleep and wakefulness.